Having worked as a postdoc at ULB I'd agree with the above - they are beginning just occasionally to appoint people who didn't do all their degrees there but in the humanities non-Belgians are still a rarity. But what I would suggest is trying to make some contacts in Belgium as their funding council FNRS has a scheme to sponsor visiting professors so you could go for 6-12 months, see how you liked it etc if you could get someone to successfully sponsor you.
Luxembourg - I heard that they were extending their one year university college (students then have to study abroad) to be a proper university but I really wouldn't reccommend it for meaningful research.
France - next to impossible to get into a permanent post if you are a) not French and b) didn't do your PhD there BUT again like Belgium there are often interesting shorter term possibilities. There's lots of information and links at
www.emploi-scientifique.infoSwitzerland - I have the impression that it has a more open academic job market than the others. A lot get posted at
www.telejob.ch, others can be found occasionally on
www.academics.de and
www.jobs.ac.ukBonne chance!